A method and device for rapidly, non-invasively and inexpensively differentiating between allergic rhinitis, upper respiratory tract viral infection and bacterial sinusitis, comprising a support strip upon which is fixed discrete indicators of pH, protein content, nitrite content, esterase activity, and eosinophil content of a sample with which said reagent test strip is contacted. Contact of a nasal secretion with the device of this invention permits differentiation between allergic, bacterial and viral conditions, based on pH, protein content, esterase activity, nitrite content, and eosinophil content.